Spray nozzles



Feb. 14, 1967 E. J. OBRIEN 3,304,013

SPRAY NOZZLES Original Filed May 1, 1963 2 Sheets-Sheet 1 E. J. OBRIENSPRAY NOZZLES Feb. 14, 1967 2 Sheets-Sheet 2 Original Filed May 1 1963 fw X W. [5 4 M Z w Z! Z W 54; {M m V1 M 5 6 .0/ .02 .03 .04 .05 .06 7.46.09 d Z J? 4 A6" a ./7 J6 United States Patent 3,304,013 SPRAY NOZZLESEdward J. OBrien, Glen Ellyn, 11]., assignor to Spraying Systems Co., acorporation of Illinois Original application May 1, 1963, Ser. No.277,269.

Divided and this application June 3, 1965, Ser. No.

7 Claims. (Cl. 239-468) This application is a division of application277,269, filed May 1, 1963, now abandoned.

This invention relates to spray nozzles of the kind wherein the liquidpasses into a whirl chamber where rotating motion is imparted theretoand thereafter passes axially of the whirl chamber through a dischargeorifice in the form of a hollow conical spray. More particularly theinvention relates to spray nozzles of the aforesaid character whereinthe whirl chamber is provided as a separately formed, and readilyreplaceable element.

In spray nozzles, of the type generally known as whirl spray nozzles,the discharge orifice is formed as a circular outlet coaxially formed atone end of a generally cylindrical whirl chamber. Water or other liquidis introduced tangentially as a high speed jet into the whirl chamber sothat the liquid is given ahigh speed whirling movement within thechamber. This rapidly whirling liquid passes through the axiallydisposed orifice, and because of the whirling motion thereof, is emittedfrom the orifice as a hollow conical spray.

The nature of spray nozzles of the aforesaid character is such thatthere is a'whirlpool or cavitation effect that forms an elongated cavityor air column which desirably extends centrally through the sprayorifice and through the Whirl chamber and to or substantially to theopposite or bottom wall of'the whirl chamber.

. It has been recognized for many years that uniformity of the hollowconical spray is dependent upon maintaining the whirling mass of waterin a substantially centered or axial relationship with respect tothedischarge orifice. Conversely, a mislocated air column results in apoor spray pattern. Control of the location of the cavity or air columnthus becomes essential to the production of the desired balanced spray.

Different devices have been employed for controlling the location of thecavity or air column in the whirling mass of water so as to obtain thedesired balanced conical spray. One such device is shown in WahlinPatent 2,247,897, patented July 1, 1941. In this structural arrangement,a central depression or pocket is formed in the bottom wall of the whirlchamber. This construction has been effective in creating the desiredspray, but because it maintains the air column in a substantially sameposition at all times, a pronounced wearing action takes place in thearea Where the air column engages the depression or pocket. As a result,a hole is ultimately produced through the bottom wall of the chamber.

Concentration of wear has required further structural modifications tobe made in spray nozzles of the aforesaid character. One of suchmodification is the use of a removable bottom plug at the bottom of thecentral depression of the whirl chamber. The removable plug isconveniently made of a hard, wear-resistant material, and of course isperiodically replaceable.

Another type of device that has been utilized to produce a conical spraypattern is that shown in Wahlin Patent 2,666,669. This patent disclosesa whirl chamber comprising a cylinder having an orifice and a separatelyformed and readily replaceable fiat bottom wall. A tangential inlet isprovided by forming a passage in the cylinder wall.

Still another device involved the use of a separately fihdfi l 3Patented Feb. 14, 1967 formed Whirl chamber with an integral bottomwall, a tangential inlet near the bottom wall and a central recess orcavity in the bottom wall for maintaining the air column in the propercoaxial relationship. This separately formed whirl chamber was then heldin place by compression spring means opposite a discharge orifice memberand within a nozzle body. This last-mentioned structural arrangement hasbeen widely used, but is burdened with the problem of excessive wear atthe bottom of the centering pocket.

In view of the undesirable wear characteristics encountered in whirlchambers, efforts have been made to reduce the wear on the bottom wallof the whirl chamber by utilizing the teachings of OBrien Patent2,815,248, patented December 3, 1957. In the aforesaid OBrien patent,the whirl chamber is formed directly in the nozzle body, and a portionof the bottom wall of the whirl chamber is formed as a fiat slopingsurface. This sloping surface was found to have an advantageouscontrolling effect on the whirling water or other liquid within thewhirl chamber, and a balanced hollow conical spray was produced, whileat the same time minimizing the wear on the bottom of the whirl chamber.For many years those skilled in the art have tried to adapt the slopingbottom principle of the aforesaid OBrien patent to spray nozzles of thekind having removable and separately formed whirl chambers. Theseefforts showed that the production of a balanced hollow conical spray iscritically related to the path of the liquid through the hollow inletbody of the nozzle, to the relative size and position of the tangentialinlet of the whirl chamber to the slope of the bottom. Prior efforts toutilize the sloping bottom principle in this general type of spraynozzle have until the present invention, been unsuccessful.

It is the primary object of the present invention to provide a new andimproved whirl spray nozzle of the sloping bottom type. An objectrelated to the foregoing is the provision of such a spray nozzle whereina slope bottom whirl chamber may be utilized in a removable orreplaceable relationship While at the same time assuring the productionof a balanced hollow conical spray.

More specifically it is an object of this invention to provide a spraynozzle utilizing a separately formed slope bottom whirl chamber elementassociated with other elements of the nozzle as an independent assemblythat may be used in the same form with inlet bodies ofdifferent types.

Other and further objects of the present invention will be apparent fromthe following description and claims, and are illustrated in theaccompanying drawings, which, by way of illustration, show a preferredembodiment of the present invention and the principles thereof, and whatis now considered to be the best mode in which to apply theseprinciples. Other embodiments of the invention embodying the same orequivalent principles may be used and structural changes may be made asdesired by those skilled in the art without departing from theinvention.

In the drawings:

FIG. 1 is an enlarged vertical section taken through an exemplary spraynozzle embodying the features of the invention, the spray nozzle in thisinstance having an inlet body where the inlet passage is coaxial withthe discharge orifice of the nozzle;

FIG. 2 is a plan view of a retainer member used to hold the Whirl spraychamber in place;

FIG. 3 is a side elevation of an exemplary, separately formed slopebottom whirl chamber, embodying the present invention and adapted foruse in the nozzle of FIG. 1;

FIG. 4 is a transverse cross section of the whirl chamber of FIG. 3taken along lines 44 thereof;

FIG. 5 is a section of the whirl chamber of FIG. 3 taken substantiallyalong the line 5-5 of FIG. 4;

FIG. 6 is a view similar to FIG. 1 but in partial vertical sectionshowing the invention embodied in the spray nozzle having a female typelateral connection for the inlet passage to the inlet body; and

FIG. 7 is a graph of the relationship between inlet orifice diameter andslope angle for a given whirl chamber of FIGS. 3-5.

Referring to FIGS. 1 and 6, there is shown a spray nozzle 10,constructed in accordance with the present invention.

For purposes of this description, the invention is herein disclosed asembodied in a spray head 11 of familiar construction, adapted forassociation with different types of inlet bodies 14, such as exemplifiedin FIGS. 1 and 6. As will be seen, the inlet bodies may be straight orangular, having either male or female outlet fittings. In accordancewith the present invention, the spray head 11 receives a separatelyformed, slope bottom whirl chamber 15 in such a way that when assembledwith an inlet body, a uniform and balanced hollow cone spray S isinvariably produced.

As seen in FIGS. 1 and 6, the respective inlet bodies have a relativelylarge diameter bore 16 extending therethrough defining a liquiddistributing chamber 20. In order to receive a spray head assembly, thelower portion of the bore is internally screw threaded at 22.

The inlet body 14 has a liquid inlet passage 24 opening through the backwall 26, coaxial with the distributing chamber 20. The upper portion ofthe passage is suitably internally threaded at 27.

The spray head assembly 11 comprises, in keeping with the invention, acap having a reduced upwardly projecting (as seen in the drawings)nipple 32 that is externally threaded at 33 so that it may bescrewedinto the threads 22. An upwardly facing shoulder 38 is formed about thelower end of the nipple 32 for receipt of a gasket 40 so that the capmay be sealed against the opposed surface 42 of the inlet body. Theinner surface of the nipple 32 defines a mounting chamber 45 ofconveniently greater diameter than the Whirl chamber 15. The chamber 45has a reduced forward end portion 47 that has a diameter just slightlygreater than the outer diameter of the whirl chamber 15. The reducedportion 47 terminates short of the lower face of the cap 30 so that aforward cross wall 50 is provided for the cap. In this cross wall 50,and coaxially with respect to the mounting chamber 45, a tapered bore 53is provided through the wall, thereby providing a seat for acomplementary sized orifice insert 55. The insert 55, in the illustratedform, has an outer tapered surface complemental to the tapered seat 53,so as to permit press fitting engagement and a central cylindricalopening 57 defines the discharge orifice for the spray head. As will beobserved, the upper portion of the orifice opening 57 is formed with ashallow tapered countersink 60.

The slope bottomed whirl chamber 15 has a generally cup-shaped form, andis adapted to be placed in inverted relationship (FIGS. 1 and 6) in themounting chamber 45 with its open, lower end, located in, and guidedlaterally by, the reduced portion 47. The transverse face of the wall ofthe open lower end of the whirl chamber 15 is substantially planar, andrests on the upper edge of the orifice insert 55. The closed, upper end(as seen in FIG. 1) of the whirl chamber 15 is engaged by removable Tshaped retaining plug member 62 having its peripheral edge screwthreaded to permit engagement with internal screw threads 64 formed onthe nipple 32.

The retaining member 62 has an upstanding central cylindrical stem 66that facilitates handling and insertion of the member in the nipple 32.A transverse slot 69 in the upper end of the stem 66 receives anappropriately shaped tool for tightening the member in position to holdtnue slope angle phi to the size of the inlet diameter.

4 the whirl chamber 15 against the orifice insert 55 in sealingrelation, these elements together defining an independ-- ent assemblyfor receipt in an inlet body 14.

The member 62 has a plurality of flow stabilizing passages 71 (FIGS. 1and 6) that extend downwardly therethrough in equally spacedcircumferential relationship about the stem. In the present instancefour such passages 71 are shown, but more or less may be used.

It will be noted that the height of the stem 66 is, in each instance,such that it terminates short of the upper wall of the inlet chamber 20,and the relative length of the nipple 32 is such that when the sprayhead 11 is associated with angular inlet bodies such as shown in FIG. 6,the upper end of the nipple is located at or downwardly from thelowermost portion of the lateral inlet passage permitting unrestrictedflow of fluid to the chamber 20.

As shown particularly in FIGS. 3, 4 and 5, the separately formed whirlchamber 15 has a generallycup-like profile in section, and may be madeby any suitable known process, but preferably from a hard material suchas tungsten carbide or chrom carbide. The member 15 generally comprisesa bottomwall and an integrally formed cylindrical side wall 82, togetherdefining a cylindrical inner chamber 85. The inner bottom wall will beseen to slope, lying in a plane containing, for identification purposes,a line 87. The line 87 defines an acute angle phi with respect toanother identification line 89 disposed perpendicular to thelongitudinal axis AA of the chamber, and this angle is the true slopeangle of the chamber bottom.

Extending through the side wall 82 of the whirl chamber, an inletpassage is formed. The passage breaks through the inner wall at a point97, tangent to the side wall of the chamber so that liquid entering thepassage is impelled about the smooth periphery of the chamber, therebyimparting a whi-rlingmotion.

In keeping with the invention, the inlet is disposed at short distancefrom the intersection of the side and bottom wall. Ideally, a distancebetween the axis of the inlet and the bottom of about 0.062 inch plusthe radius of the in= let passage provides not only optimum wearcharacteris tics, but a stable and excellent spray pattern. On thedrawings (FIG. 3) this dimension would be C. It has been found thatvariations from this dimension first re= sult in deterioration ofwearability, but a certain amount is permissible in order to gain themanufacturing advan= tage' of forming the inlet on a jig using the samecenter for various diameters. Naturally, the smaller the diameter, thegreater the distance C becomes.

Further, in keeping with the invention, the bottom surface of thechamber is formed so that the deepest portion thereof, shown in FIGS. 3and 5 as a point 100, is located in a particular relationship withrespect to the inlet passage 95.

With reference particularly to FIG. 4, in order to develop a desirablespray pattern, placement of the inlet must be proper with respect to theposition of the shape of the slope. Thus, the axis, identified as line102, of the inlet bore and the line 87 lying in the plane of the slopedefine an angle theta (0). This angle is preferably between 30 and 50,and ideally between 40 and 45. Variations within this range may bemeasured by dis placement of the highest point of the slope to the rightor left of its indicated position, as'seen in FIG. 4 and identified aslines and 112. Lines 110 and 112 WhlCh pass through the highest pointand the axis of the chamber thus define the position of the plane of theslope relative to the inlet hole 95.

Still another parameter is involved in achieving the desirable result ofthe present invention. Uniform spray patterns, as previously noted,arise through maintenance of a properly formed and positioned air core.Important to this performance factor is the relationship of the Theordinate is divided into units of 1 of slope, and the abscissa intounits of equal length, defining units of 0.010 inch of orifice diameter.This relationship has been plotted, and appears as FIG. 7. It will beseen that a range of approximately 12 is permissible to obtain thedesired results.

Specific measured relationship for optimum performance show that for aninlet diameter of .067 inch the angle phi is 2. This is point 120 on thegraph. For greater capacity, the orifice diameter may be increased forexample to a .096 inch and the slope angle phi becomes 3, point 122 onthe graph. Likewise, a diameter of 0.109 inch relates to an optimumslope of 4", point 124 on FIG. 7. Broadly considered, as the diameter ofthe tangential inlet passage 95 is increased, the slope of the bottomsurface is increased. As seen in FIG. 7, above orifices sizes ofapproximately 0.11 inch, the relationship approaches 1:1.

Orifice inserts 55 of different diameters are conventionally employedwith any selected size of inlet opening 95 to obtain variations incapacity and spray angle, and this is influenced by the pressure in theliquid being sprayed. The range of diameters of the orifices oftenemployed is from .055 inch to .250 inch, and by difierent oombinationsof inlet diameter and orifice diameter a wide range of output capacitiesand spray angles may be obtained for the input pressure that is to beinvolved.

Referring again to FIGS. 1 and 6, it will be observed that when liquidenters the relatively large distributing chamber 20 there is a reductionin flow velocity. The liquid then flows axially through the severalstabilizing flow passages 71 so that regardless of the direction ofentry of the liquid into the distributing chamber 20, the flow of suchliquid into the chamber 45 is the same. Such flow through the equallyspaced stabilizing passage 71 is thus evenly distributed about the axisof the chamber 45, and the change of direction of flow that is requiredfor this liquid to enter the tangential passage 95 remains the sameregardless of the rotative position of the whirl chamber 15 within thechamber as determined by the tightening of the threaded cap into theinlet.

In the proportion shown in the drawings, the spray nozzles of all of theforms shown are such that even though liquid enters the chamber 20 at arelatively high velocity, the larger volume of the chamber reduces thevelocity of the liquid to but a small fraction of the velocity at whichit entered. Thus, in the chamber 20, the liquid has a relatively largepressure head and it has lost any directional characteristics of thevelocity that it may have had as it entered. The relatively highpressure head causes the liquid to pass downwardly through the flowstabilizing passages 71 at a somewhat increased velocity, and the fiowis again balanced in the chamber 45.

Within the chamber 45. the downward velocity is again decreased, and inthe proportion shown, the downward velocity is measurable at aboutone-third of the velocity of the liquid as it moves through the passages71. Thus, regardless of the relative inlet direction of the inletnassages, the liquid in every instance loses its original directioncharacteristics in the distributing chamber 20 and enters the chamber 45in the same direction and in a balanced relationship about the annularchamber provided between the walls of the chamber 45 and the outside ofthe whirl chamber 15. This advancing liquid thus has the samecharacteristics of pressure flow direction and the like in everyinstance, and the liquid therefore is forced through the tangentialpassage 95 into the whirl chamber 15 in the same manner regardless ofthe direction of entry into the distributing chamber 20 and regardlessof rotative relationship of the whirl chamber 15 within the chamber 45.Thus, uniformity of the resulting spray S is unefiected in any way uponthe direction of the entry of liquid into the distributing chamber, noris it dependent upon the rotative position of the chamber 15 within thechamber 20.

It will be apparent therefore that the present invention provides animproved spray nozzle structure wherein the wear-resisting capabilitiesof a slope bottom whirl chamber may be effectually utilized while at thesame time assuring that the spray that is produced will be balanced inevery instance.

It will also be evident that the present invention provides a new andimproved spray head structure that is of great utility because it may beutilized in a single form for association with inlet bodies of diflerentconstruction.

Thus while a preferred embodiment of the invention has been illustratedherein, it is to be understood that changes and variations may be madeby those skilled in the art without departing from the spirit and scopeof the appended claims.

The embodiments of the invention in which an exclusive property orprivilege is claimed are defined as follows:

1. In a spray nozzle, comprising a spray head assembly removably fittedto an inlet body, said spray head defining with said inlet body arelatively large cylindrical space, and having an outlet orificedisposed in one end thereof, a cup-shaped member adapted to be removablysecured within said space with the open end thereof disposed about saidorifice in overlapping relation, said cupshaped member and spray headtogether defining a generally cylindrical whirl chamber co-axial withsaid orifice, having side walls, and an integral bottom wall oppositesaid orifice, the plane of said bottom wall being oblique to the axis ofsaid whirl chamber, an inlet passage formed through the wall of said cupmember generally transverse to the axis of said chamber and terminatingin said chamber adjacent to the intersection of the side' wall and saidbottom wall so that fluid under pressure disposed in the portion of thespace about said up member is forced into said chamber through saidpassage and against the side wall and sloping bottom adjacent thereto,causing a whirling helical movement of said fluid as the same passesthrough said orifice, in an evenly dispersed conical fan.

2. A whirl spray head assembly adapted to be received in an inlet bodyto form a whirl spray nozzle comprising in combination, a cap portionhaving a cross wall and defining a chamber therein, means defining anorifice centrally disposed in said cross wall, a cup-shaped memberhaving a bottom portion and an integrally formed cylindrical walltogether defining a generally cylindrical whirl chamber, said chamberbeing coaxially disposed in overlapping relation about said orifice andin unrestricted communication therewith, the bottom wall of said chamberopposite said orifice being disposed in a plane which is obliquerelative to the axis of said chamber, means defining an inlet passage inthe cylindrical wall of said member adapted to direct fluid into saidchamber in a direction substantially tangent to the cylindrical wall ofchamber and toward the lowest point of said sloping bottom wall so thatthe fluid flows in a helical path toward said orifice, and means fittedin said cap for holding said member in rigid alignment with saidorifice.

3. A whirl spray head assembly adapted to be received in an inlet bodyto form a whirl spray nozzle comprising in combination, a cap portionhaving a cross wall and defining a chamber therein, means defining anorifice generally centrally disposed in said cross wall, a cupshapedmember having a bottom portion and an integrally formed cylindrical walltogether defining a generally cylindrical whirl chamber, said chamberbeing coaxially disposed in overlapping relation about said orifice andin unrestricted communication therewith, the bottom wall of said chamberbeing disposed in a plane which forms an acute angle relative to a planetransverse to the axis of said chamber, means defining an inlet passagein the cylindrical wall of said member adapted to direct fluid into saidchamber in a direction substantially tangent to the cylindrical wall ofchamber and toward the lowest point of said sloping bottom wall so thatthe fluid flows in a helical path toward said orifice, said angle of theplane of said sloping bottom wall being variable in direct proportion tothe diameter of said inlet passage,

and means fitted in said cap for holding said member in rigid alignmentwith said orifice.

4. In a spray nozzle, comprising a spray head assembly removably fittedto an inlet body, said spray head defining with said inlet body arelatively large cylindrical space, and having an outlet orificedisposed in one end thereof, a cup-shaped member adapted to beremov-ably secured within said space with the open end thereof centrallydisposed about said orifice in overlapping relation, said cup-shapedmember and spray head together defining a generally cylindrical, smoothwalled whirl chamber coaxial with said orifice having side walls, and anintegral bottom wall opposite said orifice, the plane of said bottomwall being oblique to the axis of said whirl chamber, an inlet passageformed through the wall of said cup member generally transverse to theaxis of said chamber and terminating in said chamber adjacent to theintersection of the side wall and said bottom wall, the slope of saidbottom wall being generally upward toward said inlet passage wherebyfluid under pressure disposed in the portion of the space about said cupmember is forced into said chamber through said passage and against theside wall and sloping bottom adjacent thereto, causing a whirlinghelical movement of said fluid as the same passes through said orifice,in an evenly dispersed conical fan.

5. A whirl spray head assembly adapted to be received in an inlet bodyto form a whirl spray nozzle comprising in combination, a cap portionhaving a cross wall and defining a chamber therein, means defining anorifice generally centrally disposed in said cross wall, a cupshapedmember having a sloping bottom portion and an integrally formedcylindrical wall together defining a generally cylindrical whirlchamber, said chamber being coaxially disposed in overlapping relationabout said orifice and in unrestricted communication therewith, meansde-- rection of said inlet passage, from a point therebelow, a

line in said plane between the lowest and highest point therewithin,said chamber defining with the axial center of said inlet passage, anacute angle, said inlet passage adapted to direct fluid into saidchamber in a direction substantially tangent to the cylindrical wall ofchamber and toward the lowest point of said sloping bottom wall so thatthe fluid flows in a helical path toward said orifice, and means fittedin said cap for holding said member in rigid alignment with saidorifice.

6. The combination as set forth in claim 5 wherein said acute angleranges between and 7. The combination as defined in claim 5 wherein theslope of the bottom wall of said chamber defines an acute angle withrespect to a line transverse to the axis thereof, said angle beingvariable in direct proportion to the diameter of said inlet passage.

References Cited by the Examiner UNITED STATES PATENTS 2,218,110 10/1940Hosmer et a1. 239468 2,247,897 7/1941 Wahlin 239-468 2,666,669 1/1954Wahlin 239468 2,815,248 12/ 1957 OBrien 239-468 FOREIGN PATENTS1,378,681 10/1964 France.

EVERETT W. KIRBY, Primary Examiner.

1. IN A SPRAY NOZZLE, COMPRISING A SPRAY HEAD ASSEMBLY REMOVABLY FITTEDTO AN INLET BODY, SAID SPRAY HEAD DEFINING WITH SAID INLET BODY ARELATIVELY LARGE CYLINDRICAL SPACE, AND HAVING AN OUTLET ORIFICEDISPOSED IN ONE END THEREOF, A CUP-SHAPED MEMBER ADAPTED TO BE REMOVABLYSECURED WITHIN SAID SPACE WITH THE OPEN END THEREOF DISPOSED ABOUT SAIDORIFICE IN OVERLAPPING RELATION, SAID CUPSHAPED MEMBER AND SPRAY HEADTOGETHER DEFINING A GENERALLY CYLINDRICAL WHIRL CHAMBER CO-AXIAL WITHSAID ORIFICE, HAVING SIDE WALLS, AND AN INTEGRAL BOTTOM WALL OPPOSITESAID ORIFICE, THE PLANE OF SAID BOTTOM WALL BEING OBLIQUE TO THE AXIS OFSAID WHIRL CHAMBER, AN INLET PASSAGE FORMED THROUGH THE WALL OF SAID CUPMEMBER GENERALLY TRANSVERSE TO THE AXIS OF SAID CHAMBER AND TERMINATINGIN SAID CHAMBER ADJACENT TO THE INTERSECTION OF THE SIDE WALL AND SAIDBOTTOM WALL SO THAT FLUID UNDER PRESSURE DISPOSED IN THE PORTION OF THESPACE ABOUT SAID UP MEMBER IS FORCED INTO SAID CHAMBER THROUGH SAIDPASSAGE AND AGAINST THE SIDE WALL AND SLOPING BOTTTOM ADJACENT THERETO,CAUSING A WHIRLING HELICAL MOVEMENT OF SAID FLUID AS THE SAME PASSESTHROUGH SAID ORIFICE, IN AN EVENLY DISPERSED CONICAL FAN.